Abstract:
Interfacial interaction is investigated between the two basic
constituents in Carbon Fiber Reinforced Plastics (CFRPs). Efforts have been
made to quantify the Interfacial Shear Strength (IFSS) between individual
Carbon Fiber (CF) and epoxy matrix in CFRPs by performing single fiber
micro-droplet debond test. Initially, IFSS of the epoxy composites reinforced
with unsized or Heated Carbon Fiber (HCF) is assessed. Study is then
extended to assess the IFSS of Carbon Nanotubes (CNTs) based CFRP
hybrid composites. The hybrid composites are prepared by reinforcing epoxy
matrix with CNT grafted Carbon Fibers (CNTCF). The versatile, simple and
time effective method of chemical vapor deposition is used to synthesize
CNTs directly on the surface of CF. IFSS is found to enhance after the
inclusion of grafted CNTs in CFRP composites. Keeping in mind the
application view point of CFRPs to put up with varying loads, effect of
loading rate on the IFSS of CFRPs is also examined. To this end, both
HCF/epoxy and CNTCF/epoxy composites are debonded at cross-head
rates varying by two orders of magnitude and IFSS values are compared.
Finally, scanning electron microscopy of debonded fibers is carried out to
understand the interfacial failure mechanism in various composites.
